1. Field
Aspects herein relate to porous three-dimensional networks of polyurethane, uses thereof, and methods of preparation. For example, the porous networks of polyurethane may include a polyurethane aerogel material.
2. Discussion of Related Art
Aerogels are three-dimensional assemblies of nanoscale, nanostructured, or nanofeatured particles that are highly porous materials exhibiting ultra-low densities. Aerogel materials are typically produced by forming a gel containing a liquid component and a porous solid component and removing the liquid by supercritically or subcritically drying the wet gel to leave behind the porous solid. Supercritical drying involves the solvent being transformed into a vapor above its critical point and allowing the vapor to escape in a way that leaves the porous solid structure intact.
The large internal void space in aerogels generally provides for a material with low dielectric constant, low thermal conductivity, and high acoustic impedance. Aerogels have been considered for a number of applications including thermal insulation, lightweight structures, and impact resistance.